1. Field of the Invention
The present invention relates generally to medical devices and, more particularly, to laser handpieces.
2. Description of Related Art
Radiation delivery systems are typically used to transport electromagnetic energy from electromagnetic energy sources to treatment sites. One common radiation delivery system can comprise a cylindrically-shaped fiber optic tip from which electromagnetic energy is emitted in a direction toward the treatment site.
In certain applications, radiation delivery systems can be engineered to generate predetermined beam shapes and spatial energy distributions. The energy distribution of a simple delivery system, comprising a fiber optic tip, can be described as having a circular illumination area, with a so-called Gaussian distribution of beam intensities being spatially distributed within the illumination area. For instance, the illumination area from a fiber optic tip can comprise a central high-intensity area or “hot spot” surrounded by peripheral areas of lower intensity.
Regarding energy distributions, some beam profiling applications can require or would be optimized with radiation delivery systems capable of generating illumination areas of relatively uniform density across parts or all of the illumination area. Moreover, it may also be desirable to generate non-circular illumination areas, or to generate electromagnetic radiation having predetermined energy distributions across a non-planar illumination area. Use of laser radiation having a relatively uniform power distribution over a particularly shaped area can be a practical task for multiple medical applications. In seeking to generate predetermined energy distributions, prior-art systems have implemented relatively complex optical schemes with multiple optical elements, which systems can be relatively large and/or inefficient. A prior-art system may comprise, for example, a relatively large length, e.g., about 100 mm to 150 mm, measured from the trunk fiber to the output end of the system and measured in a direction normal to the target. Regarding efficiency, implementation of a diffuser in front of a prior-art fiber optic end together with a mirror reflector may not eliminate the “hot spot” problem and may introduce losses of laser power, which configuration can undesirably result in an efficiency as low as about 50%.